New design for reducing interfacial stresses of reinforced structures with FRP plates

2019 ◽  
Vol 37 (2) ◽  
pp. 196-207 ◽  
Author(s):  
Youssouf Belabed ◽  
Bachir Kerboua ◽  
Mostapha Tarfaoui
Keyword(s):  
Composite Structures ◽  
Adhesive Layer ◽  
Design Solution ◽  
Element Analysis ◽  
Interfacial Stresses ◽  
Reinforced Polymers ◽  
Content Type ◽  
Lag Effects ◽  
Frp Composites ◽  
Optimal Configurations

Purpose The sustainability of the structures is not only a technical goal, but also a matter of social and environmental values. This requires the researchers to use very rigid, highly durable and corrosion-resistant composite structures in order to achieve the technical, environmental and social goals. The purpose of this paper is to present an original work on reducing the interfacial stresses of bonded structures with fibre-reinforced polymers (FRP) plates based on new taper design. Design/methodology/approach In this proposed concept, the effect of combined taper is investigated on reducing interfacial stresses, attempting to enhance the structure performance and address the debonding problem that comes with reinforcing techniques. This research is carried out by using finite element analysis, incorporating many new parameters. Findings As a result, a new solution is discovered that combined taper in both adhesive layer and composite laminate, which significantly reduces the interfacial stresses at the end of the FRP plate. Additionally, a parametric study is carried out in order to determine the optimal configurations of taper dimensions as well as other parameters that influence the stress concentration distribution at the edge of the adherends. Practical implications This new design regarding the reduction of interfacial stresses will help in increasing the lifespan of damaged structures reinforced by FRP composites, preserving thus its technical, historical and social values. Originality/value The paper uses straight, concave and convex fillets with inverse taper as a new design solution with new parameters including thermo-mechanical loads and pre-stressed FRP plate with multi-layer, fibre orientation and shear-lag effects.

Towards hybridization of composite patch in repair of cracked Aluminum panel

2019 ◽  
Vol 10 (6) ◽  
pp. 868-887
Author(s):  
Alpesh H. Makwana ◽  
A.A. Shaikh
Keyword(s):  
Stress Intensity ◽  
Carbon Fiber ◽  
Hybrid Composite ◽  
Adhesive Layer ◽  
Patch Repair ◽  
Element Analysis ◽  
Interfacial Stresses ◽  
Content Type ◽  
Composite Patch ◽  
Repair Efficiency

Purpose The maintenance of aircraft structure with lower cost is one of the prime concerns to regulatory authorities. The carbon fiber-reinforced polymer (CFRP) patches are widely used to repair the cracked structure. The demands and application of CFRP compel its price to increase in the near future. A distinct perspective of repairing the cracked aluminum panel with the hybrid composite patch is presented in this paper. The purpose of this paper is to propose an alternative patch material in the form of a hybrid composite patch which can provide economical repair solution. Design/methodology/approach The patch hybridization is performed by preparing the hybrid composite from tows of carbon fiber and glass fiber. Rule of hybrid mixture and modified Halpin–Tsai’s equation are used to evaluate the elastic constant. The stress intensity factor and interfacial stresses are determined using finite element analysis. The debonding initiation load is evaluated after testing under mode-I loading condition. Findings The hybrid composite patch has rendered the adequate performance for reduction of stress intensity in the cracked panel and control of interfacial stresses in the adhesive layer. The repair efficiency and repair durability of the composite patch repair was ensured by incorporation of the hybrid composite patch. Originality/value The studies involving patch hybridization for the application of composite patch repair are presently lacking. The influence of the patch stiffness, methodology to prepare the hybrid composite patch and effects of hybridization on the performance of composite patch repair is presented in this paper.

Nonlinear FE simulations of structural behavior parameters of reinforced concrete beam with epoxy-bonded FRP

2015 ◽  
Vol 24 (1-2) ◽  
pp. 35-46 ◽  
Author(s):  
Saptarshi Sasmal ◽  
S. Kalidoss
Keyword(s):  
Reinforced Concrete ◽  
Numerical Models ◽  
Adhesive Layer ◽  
Control Mode ◽  
Hydraulic Actuator ◽  
Element Analysis ◽  
Interfacial Stresses ◽  
Rc Structures ◽  
Laminate Thickness ◽  
Reinforcement Strain

AbstractIn the present study, investigations on fiber-reinforced plastic (FRP) plated-reinforced concrete (RC) beam are carried out. Numerical investigations are performed by using a nonlinear finite element analysis by incorporating cracking and crushing of concrete. The numerical models developed in the present study are validated with the results obtained from the experiment under monotonic load using the servo-hydraulic actuator in displacement control mode. Further, the validated numerical models are used to evaluate the influence of different parameters. It is found from the investigations that increase in the elastic modulus of adhesive layer and CFRP laminate increases the interfacial stresses whereas increase in laminate modulus decreases the displacement and reinforcement strain of the beam. It is also observed that increase in the adhesive layer can largely reduce the interfacial stresses, whereas increase in laminate thickness increases it. However, increase in laminate thickness decreases the displacement and reinforcement strain of the beam significantly. It is mention worthy that increase in laminate length reduces the interfacial stresses, whereas CFRP width change does not affect the interfacial stresses. The study will be useful for the design and practicing engineers for arriving at the FRP-based strengthening schemes for RC structures judiciously.

Three-dimensional finite element analysis for temperature filed of composite materials during the cure

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhangxin Guo ◽  
Zhiqiang Yu ◽  
Shiyi Wei ◽  
Guoliang Qi ◽  
Yongcun Li ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Three Dimensional ◽  
Arbitrary Geometry ◽  
Element Analysis ◽  
Finite Element Program ◽  
Content Type ◽  
Dimensional Finite Element ◽  
Element Program

PurposeThe cure simulation of composite structures with arbitrary geometry can be investigated by the finite element program.Design/methodology/approachFinite element method is employed in this work.FindingsThe simulated results match the experimental results well, which demonstrates the finite element analysis models are reliable. Compared with the one- and two-dimensional finite element analysis, temperature and degree of cure can be calculated at any point within composite structures in the present simulation analysis. The cure simulation of composite structures with arbitrary geometry can be investigated by the finite element program.Originality/valueA coupled thermokinetic simulation of the liquid composite molding process based on a three-dimensional finite element method is presented. The cure simulation of composite structures with arbitrary geometry can be investigated by the finite element program.

scholarly journals Strength Prediction of Adhesively-Bonded Scarf Repairs in Composite Structures under Bending

2010 ◽  
Vol 636-637 ◽  
pp. 233-238 ◽  
Author(s):  
Raul D.S.G. Campilho ◽  
Marcelo F.S.F. de Moura ◽  
A.M.G. Pinto ◽  
Dimitra A. Ramantani ◽  
J.J.L. Morais ◽  
...  
Keyword(s):  
Composite Structures ◽  
Mixed Mode ◽  
Failure Modes ◽  
Numerical Study ◽  
Adhesive Layer ◽  
Elastic Stiffness ◽  
Cohesive Elements ◽  
Adhesively Bonded ◽  
Element Analysis ◽  
Cohesive Laws

This work reports on the experimental and numerical study of the bending behaviour of two-dimensional adhesively-bonded scarf repairs of carbon-epoxy laminates, bonded with the ductile adhesive Araldite 2015®. Scarf angles varying from 2 to 45º were tested. The experimental work performed was used to validate a numerical Finite Element analysis using ABAQUS® and a methodology developed by the authors to predict the strength of bonded assemblies. This methodology consists on replacing the adhesive layer by cohesive elements, including mixed-mode criteria to deal with the mixed-mode behaviour usually observed in structures. Trapezoidal laws in pure modes I and II were used to account for the ductility of the adhesive used. The cohesive laws in pure modes I and II were determined with Double Cantilever Beam and End-Notched Flexure tests, respectively, using an inverse method. Since in the experiments interlaminar and transverse intralaminar failures of the carbon-epoxy components also occurred in some regions, cohesive laws to simulate these failure modes were also obtained experimentally with a similar procedure. A good correlation with the experiments was found on the elastic stiffness, maximum load and failure mode of the repairs, showing that this methodology simulates accurately the mechanical behaviour of bonded assemblies.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Behaviour of Axially Loaded Composite Wall Panel by Using Finite Element Analysis

2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Element Analysis ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Non Linear ◽  
Composite Wall ◽  
Experimental Values ◽  
Civil Engineering Infrastructure

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.

Bond Thickness Effects upon Dynamic Behaviour in Adhesive Joints

2010 ◽  
Vol 97-101 ◽  
pp. 3920-3923 ◽  
Author(s):  
Xiao Cong He
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Behaviour ◽  
Adhesive Layer ◽  
Adhesive Joints ◽  
Response Functions ◽  
Frequency Range ◽  
Element Analysis ◽  
Cantilevered Beam ◽  
Different Thickness

The influence of adhesive layer thickness on the dynamic behaviour of the single-lap adhesive joints is investigated in this paper. The ABAQUS finite element analysis (FEA) software was used to predict the frequency response functions (FRFs) of the single-lap adhesive joints of different thickness of the adhesive layer. As a reference, the FRFs of a cantilevered beam without joint were investigated as well. It is clear that the FRFs of the four beams are close to each other within the frequency range 0~1000 Hz. It is also found that the composite damping of the single-lap adhesive joint increases as the thickness of the adhesive layer increases.

scholarly journals New directions for reinforced concrete coastal structures

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Steven Nolan ◽  
Marco Rossini ◽  
Chase Knight ◽  
Antonio Nanni
Keyword(s):  
Service Life ◽  
Prestressed Concrete ◽  
Composite Structures ◽  
Construction Materials ◽  
Design Guidelines ◽  
Coastal Structures ◽  
Frp Composites ◽  
The Us ◽  
Time Dependent Effect ◽  
Traditional Construction

AbstractWithin the last century, coastal structures for infrastructure applications have traditionally been constructed with timber, structural steel, and/or steel-reinforced/prestressed concrete. Given asset owners’ desires for increased service-life; reduced maintenance, repair and rehabilitation; liability; resilience; and sustainability, it has become clear that traditional construction materials cannot reliably meet these challenges without periodic and costly intervention. Fiber-Reinforced Polymer (FRP) composites have been successfully utilized for durable bridge applications for several decades, demonstrating their ability to provide reduced maintenance costs, extend service life, and significantly increase design durability. This paper explores a representative sample of these applications, related specifically to internal reinforcement for concrete structures in both passive (RC) and pre-tensioned (PC) applications, and contrasts them with the time-dependent effect and cost of corrosion in transportation infrastructure. Recent development of authoritative design guidelines within the US and international engineering communities is summarized and a examples of RC/PC verses FRP-RC/PC presented to show the sustainable (economic and environmental) advantage of composite structures in the coastal environment.

Finite Element Analysis of Composite Ceramic-Concrete Slab Constructions Exposed to Fire

2016 ◽  
Vol 861 ◽  
pp. 88-95
Author(s):  
Balázs Nagy ◽  
Elek Tóth
Keyword(s):  
Composite Structures ◽  
Elevated Temperatures ◽  
Cfd Simulation ◽  
Concrete Slab ◽  
Composite Ceramic ◽  
Reinforced Concrete Beam ◽  
Element Analysis ◽  
Standard Fire ◽  
Using Data ◽  
Dynamics Simulations

In this research, conjugated thermal and fluid dynamics simulations are presented on a modern hollow clay slab blocks filled pre-stressed reinforced concrete beam slab construction. The simulation parameters were set from Eurocode standards and calibrated using data from standardized fire tests of the same slab construction. We evaluated the temperature distributions of the slabs under transient conditions against standard fire load. Knowing the temperature distribution against time at certain points of the structure, the loss of load bearing capacity of the structure is definable at elevated temperatures. The results demonstrated that we could pre-establish the thermal behavior of complex composite structures exposed to fire using thermal and CFD simulation tools. Our results and method of fire resistance tests can contribute to fire safety planning of buildings.

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